Sandra J. Lee

Meta-Analysis of Phase II Cooperative Group Trials in Metastatic Stage IV Melanoma to Determine Progression-Free and Overall Survival Benchmarks for Future Phase II Trials

PURPOSE Objective tumor response rates observed in phase II trials for metastatic melanoma have historically not provided a reliable indicator of meaningful survival benefits. To facilitate using overall survival (OS) or progression-free survival (PFS) as an endpoint for future phase II trials, we evaluated historical data from cooperative group phase II trials to attempt to develop benchmarks for OS and PFS as reference points for future phase II trials. PATIENTS AND METHODS Individual-level and trial-level data were obtained for patients enrolled onto 42 phase II trials (70 trial arms) that completed accrual in the years 1975 through 2005 and conducted by Southwest Oncology Group, Eastern Cooperative Oncology Group, Cancer and Leukemia Group B, North Central Cancer Treatment Group, and the Clinical Trials Group of the National Cancer Institute of Canada. Univariate and multivariate analyses were performed to identify prognostic variables, and between-trial(-arm) variability in 1-year OS rates and 6-month PFS rates were examined. RESULTS Statistically significant individual-level and trial-level prognostic factors found in a multivariate survival analysis for OS were performance status, presence of visceral disease, sex, and whether the trial excluded patients with brain metastases. Performance status, sex, and age were statistically significant prognostic factors for PFS. Controlling for these prognostic variables essentially eliminated between-trial variability in 1-year OS rates but not in 6-month PFS rates. CONCLUSION Benchmarks are provided for 1-year OS or OS curves that make use of the distribution of prognostic factors of the patients in the phase II trial. A similar benchmark for 6-month PFS is provided, but its use is more problematic because of residual between-trial variation in this endpoint.

EFFECTS OF MAMMOGRAPHY SCREENING UNDER DIFFERENT SCREENING SCHEDULES: MODEL ESTIMATES OF POTENTIAL BENEFITS AND HARMS

To inform the USPSTF recommendations about breast cancer screening, Mandelblatt and colleagues developed 6 models of breast cancer incidence and mortality in the United States and estimated benefit...

An siRNA-based microbicide protects mice from lethal herpes simplex virus 2 infection.

Herpes simplex virus 2 (HSV-2) infection causes significant morbidity and is an important cofactor for the transmission of HIV infection. A microbicide to prevent sexual transmission of HSV-2 would contribute substantially to controlling the spread of HIV and other infections. Because RNA interference (RNAi) provides effective antiviral defence in plants and other organisms, several studies have focused on harnessing RNAi to inhibit viral infection. Here we show that vaginal instillation of small interfering RNAs (siRNAs) targeting HSV-2 protects mice from lethal infection. siRNAs mixed with lipid are efficiently taken up by epithelial and lamina propria cells and silence gene expression in the mouse vagina and ectocervix for at least nine days. Intravaginal application of siRNAs targeting the HSV-2 UL27 and UL29 genes (which encode an envelope glycoprotein and a DNA binding protein, respectively) was well tolerated, did not induce interferon-responsive genes or cause inflammation, and protected mice when administered before and/or after lethal HSV-2 challenge. These results suggest that siRNAs are attractive candidates for the active component of a microbicide designed to prevent viral infection or transmission.

Human Immunodeficiency Virus Type 1 V1-V2 Envelope Loop Sequences Expand and Add Glycosylation Sites over the Course of Infection, and These Modifications Affect Antibody Neutralization Sensitivity

ABSTRACT Over the course of infection, human immunodeficiency virus type 1 (HIV-1) continuously adapts to evade the evolving host neutralizing antibody responses. Changes in the envelope variable loop sequences, particularly the extent of glycosylation, have been implicated in antibody escape. To document modifications that potentially influence antibody susceptibility, we compared envelope variable loops 1 and 2 (V1-V2) from multiple sequences isolated at the primary phase of infection to those isolated around 2 to 3 years into the chronic phase of infection in nine women with HIV-1 subtype A. HIV-1 sequences isolated during chronic infection had significantly longer V1-V2 loops, with a significantly higher number of potential N-linked glycosylation sites, than the sequences isolated early in infection. To assess the effects of these V1-V2 changes on antibody neutralization and infectivity, we created chimeric envelope sequences, which incorporated a subjects V1-V2 sequences into a common subtype A envelope backbone and then used them to generate pseudotyped viruses. Compared to the parent virus, the introduction of a subjects early-infection V1-V2 envelope variable loops rendered the chimeric envelope more sensitive to that subjects plasma samples but only to plasma samples collected >6 months after the sequences were isolated. Neutralization was not detected with the same plasma when the early-infection V1-V2 sequences were replaced with chronic-infection V1-V2 sequences, suggesting that changes in V1-V2 contribute to antibody escape. Pseudotyped viruses with V1-V2 segments from different times in infection, however, showed no significant difference in neutralization sensitivity to heterologous pooled plasma, suggesting that viruses with V1-V2 loops from early in infection were not inherently more neutralization sensitive. Pseudotyped viruses bearing chimeric envelopes with early-infection V1-V2 sequences showed a trend in infecting cells with low CD4 concentrations more efficiently, while engineered viruses with V1-V2 sequences isolated during chronic infection were moderately better at infecting cells with low CCR5 concentrations. These studies suggest that changes within the V1-V2 envelope domains over the course of an infection influence sensitivity to autologous neutralizing antibodies and may also impact host receptor/coreceptor interactions.

Decision-making and quality of life in older adults with acute myeloid leukemia or advanced myelodysplastic syndrome

Older patients with acute myeloid leukemia (AML) and advanced myelodysplastic syndrome (aMDS) must decide between receiving intensive induction chemotherapy (IC) or nonintensive chemotherapy/best supportive care (NIC). Little information exists about what factors influence treatment decisions and what quality of life (QOL) is associated with treatment choices. We prospectively examined 43 patients 60 years or older who were interviewed at diagnosis and periodically over 1 year. IC choice was associated with younger age (66 vs 76 years, P=0.01) and AML diagnosis, but not with performance status, comorbidities, or QOL. In total, 63% of all patients reported not being offered other treatment options despite physician documentation of alternatives. Patient and physician estimates of cure differed significantly: 74% of patients estimated their chance of cure to be 50% or greater, yet for 89% of patients physician estimates of cure were 10% or less. IC patients experienced decreased QOL at 2 weeks, but rebounded to baseline and to NIC levels by 6 weeks. Initial QOL is not associated with treatment choice in older AML and aMDS patients. Regardless of treatment choice, patients report not being offered treatment options and overestimate their chances of cure. In IC patients, QOL decreases during hospitalization but rebounds after discharge.

Stoichiometry of Envelope Glycoprotein Trimers in the Entry of Human Immunodeficiency Virus Type 1

ABSTRACT The human immunodeficiency virus type 1 (HIV-1) envelope glycoproteins (Envs) function as a trimer, mediating virus entry by promoting the fusion of the viral and target cell membranes. HIV-1 Env trimers induce membrane fusion through a pH-independent pathway driven by the interaction between an Env trimer and its cellular receptors, CD4 and CCR5/CXCR4. We studied viruses with mixed heterotrimers of wild-type and dominant-negative Envs to determine the number (T) of Env trimers required for HIV-1 entry. To our surprise, we found that a single Env trimer is capable of supporting HIV-1 entry; i.e., T = 1. A similar approach was applied to investigate the entry stoichiometry of envelope glycoproteins from amphotropic murine leukemia virus (A-MLV), avian sarcoma/leukosis virus type A (ASLV-A), and influenza A virus. When pseudotyped on HIV-1 virions, the A-MLV and ASLV-A Envs also exhibit a T = 1 entry stoichiometry. In contrast, eight to nine influenza A virus hemagglutinin trimers function cooperatively to achieve membrane fusion and virus entry, using a pH-dependent pathway. The different entry requirements for cooperativity among Env trimers for retroviruses and influenza A virus may influence viral strategies for replication and evasion of the immune system.

BAX protein expression and clinical outcome in epithelial ovarian cancer.

PURPOSE Expression of the pro-apoptotic protein BAX sensitizes ovarian cancer cell lines to paclitaxel in vitro by enhancing the pathway of programmed cell death. The present study was performed to determine the relationship between BAX expression and clinical outcome in 45 patients with newly diagnosed ovarian cancer. METHODS BAX protein expression was analyzed by immunohistochemistry, and its relationship with clinical outcome was determined. Assessment of BAX mRNA transcript levels and mutational analysis of the BAX coding region were also performed. RESULTS BAX protein was expressed at high levels (defined as > or = 50% of tumor cells positive) in tumor tissue from 60% of newly diagnosed patients. All patients whose tumors expressed high levels of BAX achieved a complete response (CR) to first-line chemotherapy that contained paclitaxel plus a platinum analogue, compared with 57% of patients in the low-BAX group (P = .036). After a median follow-up of 1.9 years, the median disease-free survival (DFS) of patients in the high-BAX group has not been reached, compared with a median DFS of 1.1 years for low-BAX expressors (P = .0061). BAX retained independent prognostic significance in multivariate analysis when corrected for stage and histology. BAX mRNA transcripts were easily detected in samples with low BAX protein expression, and no BAX mutations were identified. CONCLUSION The correlation between high BAX levels and improved clinical outcome suggests that an intact apoptotic pathway is an important determinant of chemoresponsiveness in ovarian cancer patients who receive paclitaxel.

Phase I study of intranodal delivery of a plasmid DNA vaccine for patients with Stage IV melanoma

Based on the likelihood of transfecting large numbers of local antigen‐presenting cells, a Phase I study in patients with Stage IV melanoma was conducted to determine the practicality, toxicity of, and immune responses to repeated infusions into a groin lymph node of escalating doses of a DNA plasmid encoding tyrosinase epitopes.

Phase III Trial of Carboplatin and Paclitaxel With or Without Sorafenib in Metastatic Melanoma

PURPOSE The primary objective of this study was to determine whether carboplatin, paclitaxel, and sorafenib (CPS) improve overall survival (OS) compared with carboplatin and paclitaxel (CP) in chemotherapy-naive patients with metastatic melanoma. PATIENTS AND METHODS In this double-blind, randomized, placebo-controlled phase III study, all patients received carboplatin at area under the [concentration-time] curve 6 and paclitaxel 225 mg/m(2) intravenously once every 21 days with random assignment to sorafenib 400 mg orally twice per day on days 2 through 19 every 21 days or placebo. The primary end point was OS, and secondary end points included progression-free survival, objective tumor response, and toxicity. RESULTS In all, 823 patients were enrolled over 34 months. At final analysis, the median OS was 11.3 months (95% CI, 9.8 to 12.2 months) for CP and 11.1 months (95% CI, 10.3 to 12.3 months) for CPS; the difference in the OS distribution was not statistically significant by the stratified log-rank test, stratified on American Joint Committee on Cancer (AJCC) stage, Eastern Cooperative Oncology Group (ECOG) performance status, and prior therapy (P = .878). Median progression-free survival was 4.9 months for CPS and 4.2 months for CP (P = .092, stratified log-rank test). Response rate was 20% for CPS and 18% for CP (P = .427). More patients on the CPS arm had grade 3 or higher toxicities (84% v 78%; P = .027), with increased rash, hand-foot syndrome, and thrombocytopenia accounting for most of the difference. CONCLUSION Sorafenib does not improve OS when given in combination with CP for chemotherapy-naive patients with metastatic melanoma. This study establishes benchmark end points for the CP regimen in first-line therapy of metastatic melanoma.

Immunogenicity and Antitumor Effects of Vaccination with Peptide Vaccine +/− Granulocyte-Monocyte Colony-Stimulating Factor and/or IFN-α2b in Advanced Metastatic Melanoma: Eastern Cooperative Oncology Group Phase II Trial E1696

Purpose: No therapy has ever shown prolongation of survival in stage IV metastatic melanoma. The association of cytokine-induced autoimmunity with improved prognosis led us to investigate the effect of multi-epitope melanoma vaccines alone and in combination with cytokines in this Eastern Cooperative Oncology Group multicenter phase II trial. Experimental Design: Eligible patients were required to have failed prior therapies and to be HLA-A2 positive. Three HLA class I-restricted lineage antigen epitopes were administered in a factorial 2 × 2 design. Peptide vaccine alone (arm A), or combined with granulocyte-monocyte colony-stimulating factor (GM-CSF; Immunex) 250 μg/d subcutaneously for 14 of 28 days each month (arm B), or combined with IFN-α2b (Intron A; Schering-Plough) 10 million units/m2 three times a week (arm C), or combined with both IFN-α2b and GM-CSF (arm D). The primary endpoint was immune response measured by enzyme-linked immunospot assay; secondary endpoints were clinical antitumor response, disease-free survival, and overall survival. Results: One hundred twenty patients enrolled and 115 patients were analyzed. Immune responses to at least one melanoma antigen were observed in 26 of 75 (35%) patients with serial samples. Neither IFN-α2b nor GM-CSF significantly improved immune responses. Six objective clinical responses were documented. At a median follow-up of 25.4 months, the median overall survival of patients with vaccine immune response was significantly longer than that of patients with no immune response (21.3 versus 13.4 months; P = 0.046). Conclusion: Immune response to vaccination correlates with prolonged survival in patients with metastatic melanoma and is not enhanced by immunomodulatory cytokines as tested in this trial.